Ultra-low sulfur diesel (ULSD) is a new standard that has been proposed by the EPA that effects diesel fuel sold for use on-road. This new regulation pertains to diesel fuel, additives and distillate fuels such as kerosene. The previous low diesel sulfur content was 500 p.p.m. (parts per million). The USLD contains only 15 p.p.m., which is about a 97 percent reduction from the 500 p.p.m. level.
The EPA requires that by Dec. 1, 2010, all highway diesel fuel sold will be ULSD. The use of ULSD will decrease emissions of sulfur compounds, which has been linked to acid rain. The decrease in sulfur content (15 p.p.m.) will reduce the replacement of particulate filters, which are being plugged up at the higher sulfur content of 500 p.p.m. The EPA hopes that the new standard will reduce the nitrogen oxide emissions by 2.6 million tons and particulate matter by 110,000 tons per year. Additionally, ULSD is required to be used in the new diesel engines or the warranty of the engines will be voided.
There are currently bench size testers that are implemented with a computer that are expensive to purchase and use. The bench size testers are not mobile and thus field inspections cannot be readily be done either at the refineries or the fueling stations. Additionally, the bench size testers require that the samples be sent to its location for analysis and that increases the time in which the results can be made available. The inspections include determining whether there has been sulfur contamination in the fuel refining system or if the fuel is over the legal limit. When sulfur reacts with oxygen it forms SO2, which can be used to test the amount of sulfur in the fuel.
Accordingly, there is a need for an apparatus and method to test diesel fuel in the field that is cost effective and the results can be determined in the field.